Variable coupling device



April 1, 1930. L. A. HAMMARLUND VARIABLE COUPLING DEVICE Filed Nov. 28, 1927 2 Sheets-Sheet l INVENTOR Lloyd Ha pun-land,

April 1, 1930. L. A. HAMMARLUND 5 VARIABLE COUPLING DEVICE Filed Nav. 28, 1927 2 Sheets-Sheet 2 Illnmlll;

Patented Apr. 1, 1930 UNITED STATES P'AT-ENTY OFFICE 1.1.021) A. rumour), or nocxvILLii cmrrnn, NEW You, ASSIGNOB To run m- MABLUND murncrunmo COMPANY. me, A conronn'rron' on NEW YORK VARIABLE COUPLING DEVICE I Application filed November 28, 1927. Serial No. 238,199.

My invention relates particularly to what are sometimes termed transformers.

One object is to provide a simple and re liable mechanism by which the coupling may 5 be varied.

V Another object is to rovide a device of this character which is e cient under all ordinary conditions of use.

Another objectis to provide a construction 1c of this character the coupling of which can be adjusted or varied automatically or by means of a screw;

Another object is to rovide a coupling device which can be rea ily attached to a con- 15 denser unit.

Another object is to rovide a coupling transformer which can lib readily o erated simultaneously with the operation a condenser.

20 In the preferred form, the invention contemplates primary and secondary coils mounted on supporting frames, one of which is slidable with respect to the other. One of the coil frames is adapted to be secured to 15 a condenser frame; the other coil frame is adapted to be moved with the rotor of the condenser. Special resilient electrical connectors are provided between fixed circuit terminals and the movable coil.

80 Fig. 1 is a side view of an automatic coupling coil embodying one form of the improvements of my invention, and showing in dot and dash lines a condenser to which the mechanism may be attached.

35 Fig. 2 is a perspective view of the coil mechanism.

Fig. 3 is a perspective view of the supporting yoke.

Fig. 4 is a plan view of the coil mecha- 40 nism.

Fig. 5 is an endview of the same.

Fig. 6 is a transverse sectional view showing the coil mechanism attached to a fragment .of the condenser frame. 7

In the form shown, the primary coilv 10 and the secondary coil 118m; mounted was to permit of relative movement of one with respect to the other for varying thg igductive relation. Each coil may be (if anaij' suitable construction with a suitable it ton for strip 13 in a suitable manner as, for instance,

holding the various turns in position. The secondary coil is secured in a suitable manner to an insulating strip 12, the opposite ends of which are secured to a heavier insulating 55 by means of hollow rivets 1d at opposite ends. The mainframe consists of these strips 12 and 13 and end brackets 15 and 16, which are secured to the strips 12 and 13 by the rivets 14. The yoke member 17 is secured to the lower feet of the brackets 15 and 16 in any suitable manner, as for instance, by means of screws 18. For convenience in attaching the mechanism tov a support, I have provided the yoke 17 with a lug 19. In this instance, the lug is designed and located so as to adapt the mechanism to be secured to frame 20 of a condenser of any suitable type. The lug has-two spaced apart fingers 21, adapted to embrace the edges of a rib 22 on a condenser 7 frame, and the lag is adapted to bevclamped to the condenser frame by a single screw 23 for passage thru the lug.

The auxiliary or supplemental frame which carries the primary coil 10 consists oi the insulating strip 25, which is secured in any suitable manner to the coil and in turn is secured to the post 23 by a screw 27. This frame has two rods 28 and 29, slidable thru' openings in the brackets 15 and 16. A stop 30, slidable on the rod 28, is adapted to be secured in place by a screw 31. A. spring 32 on the rod 28 is interposed between the stop and the bracket 16 so as to tend to draw the primary coil 10 toward and into the secondary coil 11.

The screw 33 adjustable in the post 23 presses against the bracket 16 and serves as a stop to limit the movement of the coil 10 toward the coil 11. By turning the screw 33, 90 the coil 10 may be moved toward or away from the coil 11.

.The insulating cross pieces 35 and 36 serve as supports for the conducting springs 37. Each spring has a terminal such as 38 and 39, to which connections may be readily made.

Another terminal 40 may be carried by the cross piece 35. Inthe form shown, for instance one 1 maybe connected to the terminal 39, wh ch constitutes one end of the spring connector37 and o ne of the primary coil ends ma be secured to the tip 38.

The other end of t e primary coil maybe se-" cured to the tip 41. One end of the secondary may be secured'to the terminal 40' andthe other end of the secondary may be securedto the terminal 42. The intermediate part of the primary may be connected to the terminal 43. It should be understood, of course,

that these circuit connections can be varied within the scope of'my invention.

When it is desired to have the coupler o crate simultaneously with a condenser, t a

so as to move the primary coil at the proper rate ,with respect to the change in capaclty of the condenser. It should be understood, of course, that the coils and connections may be designed for any desired circuit, as I do not consider the invention limited except by the terms of the claims or as required by the state of the-art.

In one use of the invention the movable coil 10 would be included in the anode-cathode circuit of a radio frequency amplifyingtube and the stationary coil 11 would be included in the rid cathode circuit of the following radio requency amplifying tube, and this latter coil would be tuned by a rotary variable condenser of any suitable type and secured to the inner wall of the'coil and ex tending from end to end thereof, brackets .connected to the opposite ends of-said strip;

two arallel guide rods extending throu said brackets and another coil supported y said guide rods and movable with respect to thefirst coil.

4. A construction of the character described comprising a frame, a coil sup orted by said frame at one side thereof, gm 0 rods slidable in said frame outside of said coil, a 0st connecting said guide rods outside of said frame, an insulating plate secured to. said post and a coil having one wall connected to said insulating'plate and movable therewith with respect to the first coil.

5. A construction of the character de scribed comprising a frameincluding end brackets, an insulatin brackets, a coil secure to said strip a second frame including a guide rod-slida le in said brackets, an insulating plate carried by said second frameand including an arm, having one wall supported by said arm, an insulating cross piece carried by one bracket and an insulatin cross piece formed as a part of said plate an connectin conductor stri s having their'opposite en secured to t e respective, cross bars and providing circuit terminals for the coils. -LLOYD A. HAMMARLUND.

strip connecting said a coil the coil 10 will be moved simultaneousl with v the movement of the rotor of the con sneer,

thus keeping the coupling at an optimum value for all resonant frequencies.

The cross piece 36 may conveniently be formed integral with the longitudinal strlp 25 either of one piece or a plurality of layers of insulating material and riveted or cemented to the foundation of the coil 10. The upper ends of the springs 37 may be conveniently riveted to this composite member. The cross piece 35 may also be formed of a plurality of layers of insulating material to which the lower ends of the springs 37 are riveted.

I claim:

1. A construction of the character described comprising two end brackets, two insulating strips connecting said brackets, a coil having one wall supported between said strips and a yoke connecting said brackets opposite said strips. a

2. A constructlon of the character described comprising a frame including end brackets, an insulating strip connecting said brackets, a coil having one wall supported by.

said strip, a yoke connecting the opposite sides of said brackets and providing means for supporting-said frame.

3. A construction of the character described'comprising a coil, an insulating strip 

